Conventionally, the wire-cut electrical discharge processors are sometimes used in gouging of dies. On spark discharge machining of workpiece in the wire-cut electrical discharge processors, the die plate processing is at times carried out in which a start hole is provided on the side of workpiece ordinarily called core. With the die plate processing, the wire-cut electrical discharging is completed through working steps including rough processing or cutting, semi-finishing, finishing, final finishing and so on. At the phase just before the end of a first process, hereinafter referred as first process, corresponding to the rough processing in every working step, the spark discharging comes to a halt to leave any uncut spot between the part and workpiece to keep the cut-out part or product against falling away from the workpiece. After the spark discharging has then continued on the uncut spot, the part or product is separated from the workpiece to drop under its own weight or external impact. Even if the wire-cut electrical discharge processor is energized while the part or product is in the possibility of falling away or drop from the workpiece, there occur a serious fear of damaging any of the wire-cut electrical discharge processor itself, part or product, and workpiece. Thus, it will be understood that the fear as stated earlier has to be sidestepped. Because of this, the spark discharging in the prior die plate process is temporarily withheld so as not to completely separate or cut out the part from the workpiece, and the workers break manually the uncut spots later on to separate the part from the workpiece, thereby ending the first process.
A conventional wire-cut electrical discharge machining process is disclosed in, for example patent literature 1, referred later, in which the first machining phase and the second cut-off phase are both carried out with only one processing program. With the prior wire-cut electrical discharge machining process, a cutting pathway program, uncut amount and reversing or receding amount to cut off every male pattern are set and input. The first machining phase comes to rest with leaving the uncut amount and stores the location or spot. In the second machining phase to cut off the uncut amount, the wire electrode after having gotten back from the stored location along the cutting path or kerf by the programmed uncut amount makes automatic connection and resumes the electrical-discharge at the site to cut off the male pattern.
In another patent literature 2, referred later, which is a commonly-assigned senior application, the immersion wire electrical discharge machining processor is disclosed in which the buoyancy member supports the part or product cut out from the workpiece to prevent the short-circuit which would be otherwise occur between the cut-out part and the wire electrode, thereby supporting a heavy part in safety. The buoyancy member less in specific gravity than processing liquid is underneath the workpiece. The buoyancy developed in the buoyancy member owing to the processing liquid floats the parts cut out from the workpiece by the wire electrode so as not to sink in the processing liquid.